Medically reviewed by Doru Paul, MD Key Takeaways An armpit lump, also called axillary lump, can be a symptom of breast cancer.A healthcare provider should check any hard armpit lump that doesn't ...

Cysts (fluid-filled tissue pockets), infections, and swollen lymph nodes commonly cause armpit lumps. You may see a ...

There are several causes of pain in the breast and armpit. Some of the most common causes include hormonal changes, an ill-fitting bra, or a muscle strain. Share on Pinterest Yauheni Rak/Getty Images ...